create_message_queue — Create a new empty message queue.
create_message_queue( : : : QueueHandle)
create_message_queue creates a new empty message queue.
The output parameter QueueHandle is a handle to the newly created
message queue and is used to identify the queue in any subsequent operator
calls using the queue.
The message queues are designed as FIFO pipes delivering arbitrary sets of
data safely among different threads. The queue access is internally fully
synchronized, no explicit locking is required from the application.
The data is traveling through the queue in so called messages
(see create_message).
Multiple producer threads can append data simultaneously
(enqueue_message) while multiple consumer threads are simultaneously
retrieving the data again (dequeue_message). Multiple messages
can be enqueued together using a single enqueue_message operation.
In such case, those messages will travel together through the queue
and will be delivered through a single dequeue_message call.
All the enqueued messages are copied by the
enqueue_message operation. The original message(s) can thus be
immediately reused after the enqueue_message call without affecting
the enqueued copy.
QueueHandle (output_control) message_queue → (handle)
Handle of the newly created message queue.
Number of elements: QueueHandle == 1
Assertion:
QueueHandle != 0
create_message_queue (ProducerQueue) create_message_queue (ResultQueue) * ...
Returns 2 ( H_MSG_TRUE) unless a resource allocation error occurs. Otherwise an exception is raised.
enqueue_message,
dequeue_message
clear_message_queue,
enqueue_message,
dequeue_message,
set_message_queue_param,
get_message_queue_param,
create_message,
clear_message,
set_message_tuple,
get_message_tuple,
set_message_obj,
get_message_obj
Foundation